The increasing use of fiber optic sensing systems in subterranean wells has been accompanied by the recognition that fiber optic systems can be affected over time by the harsh, hostile environment of subterranean wells. For example the combination of high temperatures and the presence of hydrogen. Hydrogen interacts with optical fibers leading to a phenomenon called hydrogen darkening that can quickly change the performance of the fiber. In extreme cases the fiber can become unusable with days after installation.
Optical fibers are often installed inside of conduits for protection and the conduit is installed in a down-hole wellbore. But even with conduits hydrogen incursion is highly likely.
Proposed solutions in the prior art have either attempted to increase the isolation of the fiber by improved barrier systems that protect the fiber or by the use of purging system that sweep the conduit with gases other than hydrogen.
There is a growing need for the improved systems for dealing with the hydrogen issue in fiber optic systems.